常用筛查方法在地中海贫血诊断中的临床应用

目的探讨常用地中海贫血(简称地贫)筛查方法红细胞平均体积(MCV)、红细胞脆性试验(一管定量法)、血红蛋白(Hb)电泳分析等单项或联合检测在地贫诊断中的应用。方法研究对象来自肇庆市第一人民医院产检、婚检及健康体检者,经基因确诊为地贫200例,非地贫80例,分析其MCV、红细胞脆性试验、Hb电泳分析等不同检测方法单项或联合检测诊断地贫的灵敏度和特异度。结果 MCV、红细胞脆性试验、Hb电泳分析等3种方法单项检测对地贫诊断的灵敏度分别为97.5%、86.0%和82.0%,特异度分别为76.3%、88.8%和93.8%,MCV与红细胞脆性试验联合检测的灵敏度和特异度分别为80.5%、90.0%,红细胞脆性与Hb电泳分析的灵敏度和特异度分别为75.5%和95.0%,MCV与红细胞脆性及Hb电泳3项联合检测的灵敏度和特异度为72.0%、100%。结论用MCV筛查地贫灵敏度较高,可作为筛查的首选方法 ,MCV、红细胞脆性试验及Hb电泳联合检测能大大提高诊断特异度。但这些方法对α地贫,尤其是轻型及静止型α地贫漏诊率较高。     

轻型地中海贫血和静止型基因携带者平均红细胞体积截断值及应用

目的探讨轻型地中海贫血（地贫）和静止型基因携带者（轻型和静止型地贫）平均红细胞体积（MCV）截断值及其应用价值。方法在南宁农村育龄夫妇地贫筛查中以血清铁蛋白正常的经基因分析确认的153例健康成人、55例β地贫杂合子、76例α地贫1、59例α地贫2和18例不贫血或只有轻度贫血的αβ复合型地贫MCV（美国雅培Cell Dyn1700血细胞分析仪检测）通过受试者工作曲线确定MCV的地贫筛查截断值，并以确定的截断值分析其临床诊断意义。结果诊断轻型和静止型地贫MCV截断值为≤78．25 fl，敏感度和特异度为85．6％和94．8％，按此截断值153例健康成人假阳性8例、59例α地贫2假阴性28例，55例β地贫杂合子、76例α地贫1和18例αβ复合型地贫无一例假阴性。结论以MCV截断值为≤78．25fl进行β地贫杂合子和α地贫1筛查有较高的应用价值。     

全血细胞计数指标对轻型地中海贫血筛查价值的探讨

目的:探讨全血细胞计数(CBC)指标对轻型地中海贫血的筛查价值。方法:分析61例轻型β地中海贫血、36例轻型α地中海贫血患者以及61例健康对照的CBC指标,对结果进行统计学分析。结果:平均红细胞体积(MCV)、平均红细胞血红蛋白含量(MCH)、MCV/红细胞(RBC)三单项指标对轻型α地贫的筛查灵敏度分别为61·11%、61·11%、63·89%,对轻型β地贫的筛查灵敏度分别为98·36%、98·36%、100%;MCV与MCV/RBC、MCH与MCV/RBC、MCV与MCH以及MCV、MCH与MCV/RBC平行联合实验对轻型α地贫的筛查灵敏度分别为72·22%、69·44%、66·67%、72·22%,对轻型β地贫的筛查灵敏度均为100%。结论:MCV/RBC用于筛查轻型地贫患者,具有较高筛查灵敏度;将其与MCV组合后建立的MCV与MCV/RBC平行联合实验具有更高的筛查灵敏度。     

红细胞平均体积、脆性以及毛细管血红蛋白电泳联合检测在产前地中海贫血诊断中的价值

目的探讨红细胞平均体积（MCV）、红细胞脆性及毛细管血红蛋白（Hb）电泳联合检测在产前地中海贫血（简称地贫）筛查诊断中的应用价值。方法对在某三级医院进行产前地贫筛查的263名孕妇同时进行MCV、红细胞脆性及毛细管Hb电泳3项血液学指标检测和中国人群常见的地贫基因突变或缺失分子生物学检测。以基因检测结果为参比标准,计算三项血液学指标单项或联合检测结果的灵敏度、特异度、准确度、阳性预测值及阴性预测值。结果 263名进行产前地贫筛查的孕妇中,56名基因检测确诊为地贫,其中α地贫37例,β地贫17例,α合并β地贫2例。MCV、红细胞脆性及毛细管Hb电泳单项检测结果对地贫诊断的灵敏度及特异度分别为82.14%和87.44%,87.50%和93.23%,53.57%和96.13%;MCV与红细胞脆性、MCV与毛细管Hb电泳、红细胞脆性与毛细管Hb电泳二项试验平行联合的灵敏度及特异度分别为96.43%和83.01%,89.29%和85.99%,96.43%和89.86%;系列联合的灵敏度及特异度分别为73.21%和97.58%,46.43%和97.58%,44.64%和99.52%。MCV、红细胞脆性和毛细管Hb电泳三项平行联合的灵敏度及特异度为100.00%和81.64%;系列联合的灵敏度及特异度为41.07%和99.52%。三项平行联合试验的灵敏度、系列联合试验的特异度,与各单项试验比较,差异有统计学意义（P〈0.05）。结论在产前地贫筛查、诊断检测中,MCV、红细胞脆性和毛细管Hb电泳三项平行联合试验可提高灵敏度,系列联合试验可增加检测特异度。     

两种方法联合检测在婚前、产前筛查地中海贫血中的应用

目的探讨采用平均红细胞体积(MCV)和红细胞脆性试验(一管法)联合检测在婚前、产前筛查地中海贫血中的临床应用价值。方法对婚前和产前检查的1738名受检者,进行血常规检测和红细胞脆性试验,比较其MCV与红细胞脆性试验结果。结果 MCV法的轻型地中海贫血检出率为11.2%(149/1328),红细胞脆性试验检出率为10.3%(137/1328)。采用两法串联,轻型地中海贫血检出率为9.8%(130/1328)。两法串联的灵敏度、特异度、阳性似然比、符合率,均高于单独MCV法、红细胞脆性试验。结论 MCV和红细胞脆性试验(一管法)联合检测是筛查地中海贫血的快速、经济,且有一定特异性、敏感性的方法,具有推广意义。     

地中海贫血实验室筛查指标评价

目的 探讨多项实验室指标用于筛查地中海贫血(简称地贫)基因携带者的临床应用价值. 方法 选取在深圳市宝安区妇幼保健院体检、婚检和产检的人员1373例,对其均进行血常规血细胞分析、血红蛋白成份分析和地贫基因诊断.以基因诊断为金标准,对已明确诊断的α-地贫组548例、β-地贫组248例、α-合并β-地贫组33例和非地贫组544例,进行红细胞参数[红细胞数量(red blood cell count,RBC)、血红蛋白(hemoglobin,HB)含量、红细胞压积(hematocrit,HCT)、平均红细胞体积(mean corpuscular volume,MCV)、平均血红蛋白含量(mean corpuscular hemoglobin,MCH)、平均血红蛋白浓度(mean corpuscular hemoglobin concentration,MCHC)和血红蛋白A2 (hemoglobin A2,HbA2)含量]比较;计算MCV、MCH和HbA23项血液学指标联合筛查结果的灵敏度、特异度、阳性预测值及阴性预测值. 结果 地贫组与非地贫组比较,地贫组HB、HCT、MCV、MCH和MCHC均减低,差异均有统计学意义(P＜0.05).与非地贫组相比较,β地贫组HbA2值明显升高(P＜0.05).MCV与MCH 2项平行联合筛查地贫的灵敏度及特异度分别为94.0％和82.9％;MCV、MCH和HbA2-HPLC 3项平行联合筛查地贫的灵敏度及特异度为97.7％和39.2％. 结论 HbA2定量分析是筛查β-地贫极有价值的实验室指标,但对于筛查α-地贫敏感性较差,漏检率高.MCV、MCH两者平行联合或与HbA2-HPLC三者平行联合筛查有较高的检测灵敏度,但特异度不甚理想.因此在进行地贫筛查时,需综合分析实验室各项指标,以降低漏诊率.     

全自动生化分析仪法测定红细胞脆性的性能研究及在地中海贫血筛查中的应用

目的应用ADVIA 2400全自动生化分析仪和武汉市长立生物技术有限责任公司生产的红细胞脆性(EFT)测定试剂盒(直接比色法)组成的检测系统,测定红细胞渗透脆性,研究自动生化仪方法学参数并验证其对地中海贫血筛查的临床性能。方法选取2016年4月我院门诊、住院患者静脉血标本共计99例,以基因检测支持的临床诊断为金标准,同时用长立试剂与实验室现用的广州米基公司红细胞渗透脆性检测(一管法)的结果进行比较。结果长立直接比色法筛查地贫的敏感度、特异度、正确率分别为85.7%、77.6%、78.8%;米基一管法筛查地贫的对应结果分别为78.6%、94.1%、91.9%。两种方法对地贫的筛查Kappa检验值为0.54,结论为一致性中等。表明长立直接比色法与米基一管法均适用于临床对地贫的筛查。结论全自动生化分析仪长立直接比色法适用于地中海贫血筛查,性能指标符合临床要求,同时能提高工作效率,减少人为误差,简便易行,适宜向地中海贫血发病率高的广大地区推广使用。     

轻型β-地中海贫血的红细胞参数分析

目的:探讨红细胞参数分析在筛查轻型β-地中海贫血中的价值。方法:用全自动血细胞分析仪对326例轻型β-地贫患者和420例正常对照者检测血常规,比较红细胞参数中RBC、Hb、MCV、MCH、RBC/Hb、RBC/MCV、RDW等指标。结果:轻型β-地贫患者的RBC、RBC/Hb、RBC/MCV、RDW均明显高于正常对照组(P<0.01),Hb、MCV和MCH均明显低于正常组(P<0.01)。结论:检测RBC、Hb、MCV、MCH、RBC/Hb、RBC/MCV、RDW等指标是大规模筛查轻型β-地贫最经济有效的方法。     

红细胞参数及血红蛋白成分分析与地中海贫血基因分型的关系探讨

目的通过检测受检人员血常规参数、红细胞渗透脆性及血红蛋白成分分析,探讨其与地贫基因分型的关系。方法采用ABX120血液分析仪检测血常规参数,"红细胞一管法"检测红细胞渗透脆性,VARII血红蛋白成分分析仪进行血红蛋白成分分析,PCR结合反向点杂交法进行地贫基因检测。结果在147例地贫基因受检者中,确诊为地贫基因患者77例,阳性率为52.4%,其中α-地贫56例,β-地贫16例,α-地贫复合β-地贫5例,且不同类型的地贫患者红细胞参数及血红蛋白成分分析结果表现各有不同,有统计学意义。结论血常规参数、红细胞渗透脆性及血红蛋白成分分析在地贫筛查中发挥着重要的作用,且可初步鉴别地贫的类型。     

%Micro/%Hypo比值在珠蛋白生成障碍性贫血和缺铁性贫血辅助诊断中的应用价值

目的探讨小红细胞百分比(%Micro)与低色素红细胞百分比(%Hypo)的比值对常见3种珠蛋白生成障碍性贫血(地贫)和缺铁性贫血(IDA)的诊断价值。方法选择49例IDA患者、24例轻型α地贫患者、24例轻型β地贫患者、24例静止型α地贫患者、120例健康体检者作为研究对象,将其分为6组:健康组、IDA组、轻型α地贫组、轻型β地贫组、静止型α地贫组、轻型地贫组(为轻型α地贫组和轻型β地贫组的合并组)。分别检测各组%Micro和%Hypo并计算出两者比值,对结果进行分析比较。结果轻型地贫组与IDA组之间,轻型地贫组、IDA组分别与健康组之间,%Micro/%Hypo比较差异均有统计学意义(P0.01)。静止型α地贫组与健康组之间,轻型α地贫组与轻型β地贫组之间,%Micro/%Hypo比较差异均无统计学意义(P0.05)。以0.9作为%Micro/%Hypo鉴别诊断轻型地贫和IDA的判别值,则其诊断轻型地贫的敏感度、特异度、准确度分别为91.67%、91.89%、91.72%,诊断IDA的敏感度、特异度、准确度分别为91.94%、91.25%、91.18%。结论 %Micro/%Hypo对轻型α地贫、轻型β地贫、IDA有较好的鉴别诊断和辅助筛查价值,对静止型α地贫的临床价值不大。     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

Dissociable correlates of two classes of retrieval processing in prefrontal cortex

Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

Clinical Pharmacokinetics of Morphine

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/ excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.